Want to cut back your electricity use at home, or go off grid altogether? There are plenty of options for fun and practical gear and appliances ranging from foot-powered washing machines to hot tubs that get their warmth from firewood. These 12 zero-energy gadgets take advantage of solar power, natural acoustics, kinetic energy and human muscle.

Window Socket Solar Charger

Mount this ingenious gadget to any sunny window and just plug your electronic devices right into it for the simplest solar-powered charger ever. The Window Socket draws energy into an internal battery, and sticks to windows with a suction plate encircling the solar panel. It’s still a concept, but it’s a particularly intriguing one, and the designers hope to increase its efficiency, charge time and energy capacity.

Koostic Zero-Energy Wood Speaker

You don’t need power to give the sound from your phone a serious boost. Simple acoustics can make a big difference, as proven by this cool wooden iPhone speaker called the Pivot. Made by Koostik, the sculptural object can be used in portrait or landscape mode and boosts sound by 2-4 times over its usual volume.

Clay Refrigerator

You don’t need a power outlet for this innovative refrigerator made entirely from clay. The MittiCool takes advantage of the natural cooling effect of water evaporation to store milk for up to three days or keep vegetables fresh for up to a week.

Human Powered Laundry Pod

Not only will this Laundry Pod use much less water and detergent to wash your clothes, it’ll do so without using any electricity, and give you an upper body workout in the process. You just fill it with water and dirty garments, add a little soap, close the cover and rotate the handle to agitate. Rinse the clothes out in a tub or sink, place them back in the pod and spin again to get rid of excess water.

Goal Zero Lighthouse Lantern

This little lantern offers the bright light of LEDs (dimmable to save energy, too) and can also charge up your phone and other small gadgets using the included hand crank or a compatible solar panel.

$40 Pedal-Powered Washer

Rather use your feet than your hands to wash your clothes the off-grid way? This clever invention costs just $40 to DIY. The GiraDora is a combination washer/spin dryer powered by a foot pedal, and was designed specifically for low-income people living in the world’s poorest nations. It’s not hard to imagine it catching on among others as well, though, like people who live or travel in RVs.

Voltmaker Kinetic Energy Charger

This rapid kinetic energy generator inspired by a ratchet system uses a whirling motion to generate a steady source of energy that can power small USB-capable devices. It’s compact, easy to use and features a built-in flashlight.

Power-Producing Camping Pot

Why should the excess energy produced when boiling water or heating up food go to waste? This cool gadget known as the PowerPot features a small thermoelectric generator attached to the bottom that produces electricity to charge USB gadgets while you’re cooking, whether you use it over a fire, a grill or on top of a stove.

DIY Enerjar Kit

Make your own energy monitor using common household materials including a glass jar, a power supply salvaged from an unused cell phone charger, and four circuit chips. The EnerJar is a low-tech DIY way to monitor how much power various devices are using.

Foot-Powered Energy Source

The Weza Portable Energy Source by Freeplay uses the power of your leg muscles for a variety of needs, from juicing up a laptop to jump-starting a car. A 12-volt DC cigarette lighter adapter makes it easy to charge various items, no matter how far away from a standard power supply you might find yourself.

Off Grid Beer Cooler

Keep beer cool year-round without using any electricity at all – or even ice. The eCool is a fun eco-friendly cooler that takes advantage of the natural coolness and steady humidity of the soil. You use a garden drill to dig a three-foot hole, insert the cooler into the ground, and you’ve got room for an entire case of beer inside.

Off Grid Hot Tub

Perched on the edge of a cliff or placed on a floating deck on a lake, this awesome hot tub can go virtually anywhere without worrying about how you’re going to provide it with electrical power. That’s because the Dutch Tub is heated using firewood, placed in a spiral attachment that naturally circulates and heats the water in the vessel.